Long stroke pump jack



Aug. 11, 1-942. L. A. BLACKBURN 2,292,427

LONG STROKE PUMP JACK Filed Oct. 21, 1939 2 Sheets-Sheet 1 PatentedAug.11, 1942 7 2,202,427 LoNG STROKE PUMP JACK Luther A. Blackburn,Altadena, Calif., assignor of one-half to Bernhard H. Scott, Glendale,

Application October 21, 1039, Serial No. 300,606

9 Claims. (CI. 74-37) This invention relates to long stroke pumps, andthe invention is particularly applicable in the construction ofdeep-well pumps. Deep-well pumps that involve the use of a reciprocatingsucker rod or pump-rod actuated at the ground level are very inefilcientdue to the lengthening of the rod on the up-stroke which, of course,reduces the efiective stroke.

The usual means for reciprocating the rod of 7 a deep-well pump is thewell-known walking beam, but practical considerations make itsubstantially impossible to obtain with it a stroke of more than four orfive feet. The present improvement involves the use of endless drivingchains that operate to reciprocate a cross-head that is connected to thepump-rod. I am aware that chain drives have been suggested heretoforefor this purpose, but they have not come into generaluse. This isprobably due to the fact that they have not provided for properlycounterbalancing the weight of the pump-rod. This involves considerabledifficulties because of the fact that on the up-stroke the load on thedriving chains includes the pump-rod and also the long column of oilsurrounding the pump-rod above the standing valve which, of course, isopen on the up-stroke.

An object of the present invention is to overcome these difi'icultiesand to provide a chain drive capable of being constructed so as toenable a relatively long stroke for the pump-rod to be attained and atthe same time provide for substantially perfect balancing of the load sothat all of the forces acting on the cross head are substantiallybalanced with reference to the axis of the rod and also in such a waythat substantially the same load is placed on the driving chains on thedown stroke as well as on the up stroke. In this way the chains operateone. substantially constant load with the stresses always acting in thesame direction in the chains.

A further object of the invention is to provide simple means foreffecting constant lubrication of the chains.

A further object of the invention is to provide means for adjusting thebearings of the sprocket wheels supporting the chains to take up wear onthe chains, and to accomplish this without interfering with the constantlubrication of the chains.

A further object of the invention is to provide adjusting means for theupper ends of the driving chains so constructed that it will providemeans for imparting the entire load from the bearing "blocks of thesprocket chains to the 55' frame of the pump, at the same time providingsimple means for efiecting their vertical adjustment when the samebecomes necessary.

In its construction the apparatus includes oppositely disposed drivechains located on opposite sides of the path of the cross head that isattached to the pump rod. In order to drive the pump rod, blocks areemployed sliding in a transverse slot in the cross head. One of theobjects of the invention is to improvethe action in a construction ofthis kind to permit relative movement of the links that are connected tothese blocks. This enables the chains to pass over the sprocket wheelswithout any danger of subjecting the connecting pin to any torsionalstrains.

A further object of the invention is to provide simple means forpreventing whipping of the chains where the. chains must be-unusuallylong to provide for an extremely long stroke in the pump.

A further object of the invention is to provide means forfacilitatingthe removal and replacement of the cross head from the crosshead guide.

Further objects of the invention'will appear hereinafter.

The invention consists in the novel parts and combination of parts to bedescribed hereinafter, all of which contribute to produce an eiiicientlong stroke pump jack.

A preferred embodiment of the invention is described in the followingspecification, while the broad scope of the invention is pointed out inthe appended claims.

In the drawings: Fig. 1 is a side elevation of a pumping apparatusembodying my invention, a portion of the cross head being broken awayand shown partially in section.- Also portions of the chains are brokenaway so as to display the cross head and contiguous parts.

Fig. 2 is also an elevation showing the side of the apparatus,illustrated in Fig. 1. In this view certain parts are broken away and atthe bottom of the figure the lubricating bath is illustrated in section,as also the cross head that is attached to the pump rod. In this viewthe upper end of the flow pipe is omitted and the pump rod is shownbroken away.

Fig. 2a is a side elevation showing the lower end of the hanger bar suchas I employ for suspending and effecting the upward adjustment of thebearing blocks for the upper sprocket wheels.

Fig. is a perspective of one of the blocks y pins or Y which I prefer toemploy for imparting movement from the chains to the pump cross head.

Fig. 4 is a vertical section showing a length of flow pipe and pump rod.

Fig. 5 is a vertical cross-section taken about on the line 5-5 of Fig. 1upon an enlarged scale, and particularly illustrating the preferreddetails of the construction for connecting the driving blocks that drivethe cross heads, that is to say, for connecting the blocks to theopposed runs of the chains that drive the same.

Fig. 6 is a vertical section taken about on the line 6-4 of Fig. 1 uponan enlarged scale, and particularly illustrating the means foradjustably supporting the upper ends of the driving chains, that is tosay, for supporting the bearing blocks for the sprocket wheels.

Fig. 'l is a horizontal secti n upon an enlarged scale taken about onthe line 'I'| of Fig. l, and particularly illustrating the arrangementof the driving chains with reference to the cross head.

Fig. 8 is a horizontal section taken about the location of the line 8-8of Fig. 1, upon an enlarged scale, certain parts being" broken away.This view particularly illustrates the means for driving the lowersprocket wheels that carry the driving chains.

Before proceeding to a more detailed description of the invention, itshould be stated that in its preferred embodiment I provide forcounterbalancinl; the cross head that is attached to the pump rod insuch a way that the forces acting on the rod are always balanced withreference to the axis of the rod.

Also in the preferred embodiment of the invention I provide four endlessdriving chains disposed in opposite pairs so that the cross head of thepump lies between the pairs of driving chains, and in such a way thattwo driving blocks or pins attached to the chains are arranged to engagethe transverse slot of the cross head. The direction of movement of thechains is such that on the upstroke these blocks are located near thepump rod and on the down stroke they are remote from the pump rod. Atall times, however, these two blocks'are equi-distant from the axis ofthe rod so that the forces exerted by them on the cross head areperfectly balanced.

Although it is not essential to the invention to provide two separatecounterweights, nevertheless I prefer to counterweight the pump rod inthat way and these counterweights are located so that any strainsdeveloped by their presence are balanced. This tends to prevent thedevelopment of vibrations at the top of the frame, where theconstruction is of vertical type, disposed in such a way as to connectdirectly to the pump rod.

. The driving chains referred to above, at their upper ends pass oversprocket wheels and likewise at their lower ends, and at these pointsthe driving blocks referred in above move apart or approach each other.These blocks are attached to special links of opposed runs of thechains. I provide a special construction for this connection that willpermit relative swiveling movement of these special links with referenceto each other, thereby improving the construcion.

The ends of the crosshead are guided by means of crosshead guides, andin order to facilitate the removal and replacement of the crosshead inthe guides I provide a special construction for the guide that willpermit this.

The bearing blocks that support the sprocket wheels at the ends of thechains, which of course support the entire load on the chains, are soconstructed that while the pump is in operation an effective clamping ofthese bearing blocks is attained on the frame, enabling the entireweight.

of the load to be imparted immediately from the bearing blocks to theframe. At the same time the construction includes means for effecting anupward adjustment of the bearing blocks when .the pump is not inoperation.

Referring more particularly to the parts, and especially the Figs. 1 and2, I provide a frame i that is preferably upright and located directlyover the flow pipe 1, and the pump rod 3 that extends up from the flowpipe, and which is reciprocated to pump the well. This frame i may be ofany suitable construction, but is preferably made up of structuralshapes such as angle iron. In order to form a guide for the cross head 4that actuates the pump rod, I prefer to provide two angle irons 5connected together back to back (see Fig. 8) forming a T-iron guide withsuperposed flanges 6 that can be engaged by the ends of the cross head 4in some manner such as indicated in Fig. 7. The cross head isconstructed with a deep transverse slot 8 (see Fig. 1). The pump rod 3passes up from below across this slot and is secured to the cross headby means of a clamp 8 that is of the usual construction, includingbolts, that can be released to enable the cross head to be adjusted toany desired position on the pump rod, or vice versa. This clamp fitsclosely into openings l0 formed in webs Ii projecting up from the upperside of the cross head so that there is substantially no play intransmitting movement to the rod from the cross head.

The chain drive for the cross head preferably comprises four endlesschains l2. These chains are disposed in pairs as illustrated in Figs. 7and 8. As shown, the chains of each pair are located respectively onopposite sides of the plane of movement of the c oss head. Correspondingruns of these pairs of chains are connected together by a connection I:(see Fig. 5) which connects the runs at the slot 8 of the cross head soas to drive the cross head up and down. This connection l3 could consistof a mere pin, but I prefer to construct it so that it includes a blockl4 having an. opening or bore l5 through the same for a driving pin topass through. Furthermore, the driving pin is preferably not constructedas a simple pin, but is 'so constructed as to give a certain amount offlexibility in the connection. This is desirable when the chain passesover the sprocket wheels at the upper and lower ends of the chains, aswill be described hereinafter. Referring to Fig. 5, I prefer to providetwo special links Ii in the chains, and these links l6 are connectedtogether by a swivel pin connection, preferably comprising a solid pinll secured to one of the links I6, which is received in the sleeve orhollow pin 18 attached to the opposite link. In addition to thisswiveling movement, it is also preferable to construct'this connectionso as'to permit the chains to move slightly'apart or toward each other.

This enables them to adjust themselves to the planes of roperfectbalance. counterweighting means carried on the frame I,

2,292,427 In the operation of the pump, the inside runs 2| of the chainsmove upwardly, so that the blocks ll on the up stroke are located nearthe middle of the cross head. In this way. these lifting forces arebrought nearer to the location of the pump rod which of course is at themiddle of the cross head.

Although the blocks I B may have plain rubbing faces on their upper andlower sides, I pre-- fer to provide anti-friction devices such asrollers 22-in their faces (see Fig. 3). The inner ends of the blocks arepreferably provided with vertical clearance grooves 23 that provideclearance for the pump rod that lies between these blocks on the upstroke.

In practising the invention I counterweight the cross head and the loadcarried by it in such a way that the force exerted by the counterweightis applied in such a way that a perfect balance results. In otherwords,- if a single counterweight were employed, the cable supporting itwould be attached at the middle of the cross head and extend upwardlyover a pulley at an elevated point above the frame, but not supported onthe frame.

However, I prefer to provide and in this instance I prefer to providetwo oppositely disposed counterweights 2 (see Fig. 1) supported on linesor cables 25 that pass upwardly from the counterweights and over sheavesor pulleys 26, the inner endsof the cables passing downwardly and beingattached to cross-pins 21 on the cross head (see Fig. 7). I prefer toprovide two of these cables 25 on each side (see Fig. 2).

Each counterweight 24 preferably consists of a plurality of weightsstacked together and tied together with a tie-bolt 28 that passesthrough all of them. This tie-bolt should fit snugly in the holes in theweights and should be clamped tight by nuts 29 on the upper ends of thetie bolts. This prevents any possibility of the individual weightsshifting out of line.

As the cables 25 are attached substantially at the middle of thecross-head on each side of the That would achieve weighed 9000 pounds,then the total load on the up stroke would be 18,000 pounds. In thatcase the counterweights should have a total weight of 13,500 pounds."This gives a net loadon the down stroke of 4500 pounds and a net load onthe up stroke of 450 pounds. This enables the motor driving the chainsto operate at a substantric motor, and this motor through. a belt 34-equal diameter and meshing together.

drives a horizontal countershaft 35 (see Figs. 1

and 8). This countershaft extends across the frame, being supported bysuitable bearings 36 and is provided with pinions 31 for driving thelower sprocket wheels 38 over which the sprocket chains run. In order toaccomplish. thi in a simple manner and to drive thechains in the properdirections, the shafts 39 of the sprocket wheels 38 are provided withgear wheels 40 of One of these wheels meshes on its outer side with thesprocket wheel 31. By reason of the fact that the chains are driven atthe base of the frame,

of course the vibration of the frame is greatly .reduced. This .greatlyreduces any tendency sprockets are mounted in suitable bearingssupsucker rod, they exert a directipull on the crosshead in perfectbalance.

The counterweights are guided on the corner angle irons 30 in the mannerindicated in Fig, 7, slide bolts 3| being provided. between the inneredges of the angle irons with keeper plates 32 bolted on each side ofthe flanges. This arrangement insures the proper guiding of thesecounterweights and prevents any lateral movement in them as they move upand down.

In order to maintain a constant load on the driving chains, that is tosay, an unvarying load, these counterweights 2% have a weight that issubstantially three-quarters of the total load on the cross head on theup stroke. For example, suppose that in a 6.000-foot well the weight ofthe pump rod is 9,000 pounds. In that case I would construct the pump sothat the weight of the column of liquid being pumped is substantiallyequal to the weight of an equal length of the pump rod. In thisconnection reference is had to Fig. 4 illustrating a length of flow pipeand pump rod. In order to determine the proper relative diameters of therod and flow pipe, it is merely necessary to proportion them so that thearea of the rod multiplied by its specific gravity is equal to the areaof the columnof liquid multiplied by its specific gravity. The resultof.this

would be that, assuming that the pump rod of line so that they will nothave any tendency to move further away from each other.

In order to maintain the chains and all parts working adjacent to themlubricated, I prefer to provide a lubricating bath or oil bath 43 (seeFig. 2) in which the lower ends of the chains dip.

. I prefer to provide a common oil bath for all four chains and permitthe pump rod 3 to pass up through it. In order to accomplish this it isnecessary to provide a sleeve or tubular housing that extends up fromthe bottom of the oil tank to a sufficient height to maintain the oillevel above the lower ends of the chains. This avoids use of astufiing-box,

As there will be considerable wear on the chains, so that they will tendto lengthen themselves, I provide means for adjusting the upperv oassist in I through horizontal flanges in a cross-bar the racks 49preferably have upwardly and outwardly inclined faces which permit thecap 50 to ride over the same in an upward direction when the bearingblocks are being adjusted upwardly. The cap bolts 50 are secured inplace by clamping bolts 52. Any suitable means may be provided foradjusting the bearing blocks 48 upwardly when the clamping bolts 52 havebeen loosened. However, I prefer to accomplish this by providingsuspending hanger bars 53 (see Fig. 1), the upper ends of which arethreaded and pass the frame. The threaded ends of these hanger barscarry adjusting nuts 55 that can be tightened up to pull the blocks 48upwardly. The lower ends of these hanger bars 53 .have eyes such as theeye 56 illustrated in Fig. 2a. These eyes are formed at lower ends ofthhanger bars will enable them'to be attached to the blocks by bolts 51.

It may be necessary from time to time-to remove the cross head 4' forrepairing the same, and in order to accomplish this I provide the crosshead guide 5 with a removable section 58 (see Fig. 1), the ends'of whichare maintained in alignment with angle irons that form this guide bymeans of clips such as the clip 59 secured in place by removable bolts.

-As the total weight of the apparatus is' not very great, even includingthe frame, it can be supported directly on the derrick floor 60. Inorder to give access to the upper end of the frame I, it may be providedwith a small ladder ii at one side and also be constructed with a crows-nest 6| near the level of the sheaves 26 and in a position'from whichthe adjusting nuts 55 can be reached whenever it is necessary to adjustthe upper sprockets.

The shafts of the lower sprocket wheels 38 are supported on inboardbearings 62 (see Fig. 8)- which are in the form of blocks and carried inthe lower ends of channel bars "that are attached at their upper ends tocross bars 54 of the frame I.

In order to enable'the inertia of the counterweights to be overcome atthe end of the down stroke, I provide the apparatus with means forattaining the effect of a flywheel. For this purpose I prefer to providea flywheel 65 on each end of the shaft 35 (see Fig. 7).

In practice, the blocks l4 should have a depth of about three-quartersof the diameter of the sprocket wheels. This seems to facilitate theirease of travel in the cross-head slot 5. It is also desirable inpractice to line the faces of the slot 8 with hardened steel wear strips8a such as illustratd in Fig. 5.

At the bottom of the down stroke, the crosshead 4 dips in the oil bath.In practice, brushes (not illustrated) 'dip in the bath and wipe theguide 5 with lubricant. As the cross-head dips in the bath the sleeve 44of the bath passes through a clearance opening 44a in the bottom of thecross-head. This is practicable because at this moment the blocks H areat the outer ends of the cross-head. Inpractice, the brushes should belocated at the ends of the cross-head to dip in the lubricant and applyit to the guideways 6 on the up-stroke.

If desired. this apparatus can be used for pull- -ing the pump-rod. Indoing this, it would be 1. In a long-stroke deep well pump, thecombination of a frame, a flow-pipe in the well, a pump-rod extendingdown into the flow-pipe, a cross-head, a driving connection between thepump-rod and the cross-head, means for guiding the cross-head toreciprocate on the frame, four endless drive chains disposed in pairswith one drive chain of each pair located on one side of the plane ofmovement of the cross-head,and the other chain of that pair located onthe other side of the plane of movement of the cross-head, a pair ofdriving-members for the cross-head corresponding to each of said pairsof driving chains and supported by the opposite runs or the said chains,a pair of oppositely disposed counterweights disposed one on each sideof the axis of the pump-rod and guided to move in a substantiallyvertical direction on said frame, the weight of the counterweights beingproportioned with respect to the weight of the pump-rod and fluidpumped, whereby the difierence in weight between the counterweights andthe weight of the fluid pumped plus the weight of the rod string on theupstroke, is substantially equal to the difierence between the weight ofthe counterweights and the weight of the rod string on the downstroke ofthe latter to insure the maintenance of a constant load on the chains inthe same direction throughout the reciprocatory movement of thepump-rod.

2. In a long-stroke deep well pump, the combination of a frame, across-head, means for guiding the same to reciprocate on the frame, apump-rod, means for connecting the pumprod to the cross-head, fourendless chains disposed in pairs with one chain of each pair located onone side of the plane of movement of the cross-head and the other chainof that pair located on the other side of the. plane of movement of thecross-head, a pair of driving members for driving the cross-head,connected to opposite runs of the said chains, means for driving saidchains, and a pair of oppositely disposed counterweights disposed one oneach side of the axis of the pump-rod, the weight of the counterweightsbeing proportioned with respect to the weight of the pump-rod and fluidpumped, whereby the difference in weight between the counterweights andthe weight of the fluid pumped plus the weight of the rod string on theupstroke, is substantiallyequal to the difference .between the weight ofthe counterweights and at the end of their down stroke.

.3. In a long-stroke deep well pump, the combination of a frame, across-head, a pump rod, means for connecting the cross-head to the pumprod to reciprocate the latter, driving means ineluding endless chainsdisposed on opposite sides of the plane of movement of the cross-head, aflow pipe in which the pump rod reciprocates,

. counterweights connected to said cross-head, the weight of thecounterweights being proportioned with respect to the weight of thepump-rod and fluid pumped, whereby the diflerence in weight between thecounterweights and the weight of the fluid pumped plus the weight of therod string .on the upstroke, is substantially equal to the differencebetween the weight of the counterweights,

and the weight of the rod string on thedown stroke of the latter to.insure the maintenance of a constant load on the chains in the samedirection throughout the reciprocatory movement of the pump-rod.-

4. In a deep well pump, the combination of a pair of drive chains, apump rod having a driving cross-head between said chains, saidcross-head having a transverse guide-way, a driving member, chainshaving special links, means connecting said driving member to saidspecial links including a swivel connection permitting nelative movementof the two special links on a transverse axis between the chains andthereby enabling the chains to adapt themselves to any irregularities offaulty alignment in the chain supports or sprocket wheels for the same.

5. In a deep well pump, the combination of a pair of drive chains, apump rod having a driving cross-head between said chains, said crossheadhaving a transverse guide-way, a driving member, chains having speciallinks, means connecting said driving member to said special linksincluding a swivel connection, said swivel connection including a pinsecured to one of the links and a sleeve'receiving the pin and securedto the opposite link, said pinand sleeve cooperating to permit relativemovement of the two special links on a transverse axis between thechains and thereby enabling the chains to adapt themselves to anyirregularities or faulty alignment in the chain supports or sprocketwheels for the same.

6. In a deep well pump, the combination of a pair of drive chains, apump rod having a driving cross-head between said chains, said crossheadhaving a transverse guide-way, a driving member, chains having speciallinks, means connecting said driving member to said special linksincluding a swivel connection, said swivel connection including a pinsecured to one of the sleeve operating to permit a limited relativelongitudinal movement of the pin and the sleeve.

7. In a pump jack for reciprocating a pumpactuating member, an endlesschain comprising a plurality of links, a pair of sprockets for thesupport of said chain, means to move said chain over said sprockets,means to transmit the motion, in two opposite directions, of one of.said links during movement of said chain to said pump-actuating member,said last-named means including a lost-motion connection between saidchain and said pump-actuating member to dissipate the motion of saidlink in a direction transverse to the motion transmitted to saidpump-actuating member, and means to counterbalance a portion of theweight suspended from the cross head on the upstroke ofsthe latter, theweight of said counterbalancing means being in excess of the weightsuspended from the cross head on the downstroke of the latter, saidexcess being, in terms of pounds, substantially equal to theuncounter-balanced portion 0! the weight suspended from thecross head onthe upstroke of the latter.

8. In a well pump having a plunger, a cross head and means to connectsaid cross head to the pump plunger, 8, chain including a. special link,means to support said chain with opposite reaches extending vertically,means to drive said chain in one direction to move said linksuccessively through said vertical reaches in opposite directions, meansto connect said link to said cross head to reciprocate the latter, acounterweight connected to said cross head to Oppose the weight of saidfirst-named means and the fluid in the well being pumped during the upstroke of the cross head, the difference between the weight of the fluidcolumn pumped plus the weight of said first-named means on the upstrokeand the weight or the counterweight being substantially the same as thediiference between the weight of the counterweight and said firstnamedmeans on the downstroke.

9. In a pump jack, a pair of vertically aligned sprockets, an endlesschain carried by said sprockets with opposite reaches of the chainextending vertically, a string of sucker rods connected to said pump,said chain including an anchor link, connecting means to connect saidlink of said chain to the sucker rod string, drive means for one of saidsprockets to move said link alternately through opposite verticalreaches of said chain, and a counterweight attached to saidafore-mentioned connecting means to oppose the weight of the sucker rodstringand' of the fluid in the well being pumped to substantiallyequalize the tension on said chain through a complete cycle of the pump.

LUTHER A. BLACKBURN.

